A row of cars is buried in the rubble of a collapsed building June 25 after a storm lashed China's Henan province. At least 20 people are dead and 33 missing after heavy rain and lightning strikes wrought havoc in China.(AFP/File/Str)

BEIJING (AFP) - At least 20 people are dead and 33 missing after heavy rain and lightning strikes wrought havoc in China, local officials and state media said.

Thousands of homes have also been destroyed or damaged.

At least 11 people were killed by mud-rock flows brought on by floods in two counties of southwest Yunnan province. Some 33 are missing and feared dead.

"If we can't find the missing people by tonight, then I think it is unlikely that we will find them at all," a civil affairs official in Yunnan told AFP.

He added that more than 3,000 houses had been damaged in the storms that have lashed the area since Monday.

Another four people died in southern Guangxi region, swept away by torrents of water and mud gushing down mountains after heavy rain pounded the area, the Xinhua news agency reported.

In neighbouring Guangdong province, five people have been killed over the past three days by lightning strikes.

Last year 48 people were killed and 39 others injured in lightning attacks in the area, Xinhua said in a separate dispatch.

Storms have lashed many parts of China over the past two weeks, leaving countless dead and millions of yuan (hundreds of thousands of dollars) in damage.

The inclement weather is an annual occurrence, with torrential rains and flooding responsible for nearly 2,000 deaths in China in the first nine months of last year, according to the latest statistics available.